Runway is a free BigCommerce inventory app from GrtLabs. It answers one question: what should I reorder? For each product it shows units sold in the last 30, 60, and 90 days, how many are on hand, and days of cover. Days of cover is on-hand stock divided by average daily sales from the last 30 days. The products that run out soonest are at the top. Download the list as a CSV and place the purchase order yourself. Example: a mug with 20 on hand that sold 60 in the last 30 days has 10 days of cover. A scarf with 40 on hand that sold none in 30 days has no days-of-cover number, so it is not treated as endless stock. Runway only reads orders, products, and inventory. It does not create purchase orders, email suppliers, or change your stock.